package com.sky.service.impl;

import com.sky.context.BaseContext;
import com.sky.dto.ShoppingCartDTO;
import com.sky.entity.Dish;
import com.sky.entity.Setmeal;
import com.sky.entity.ShoppingCart;
import com.sky.mapper.DishMapper;
import com.sky.mapper.SetmealMapper;
import com.sky.mapper.ShoppingCartMapper;
import com.sky.service.ShoppingCartService;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.time.LocalDateTime;
import java.util.List;

@Service
public class ShoppingCartServiceImpl implements ShoppingCartService {

    @Autowired
    private ShoppingCartMapper shoppingCartMapper;
    @Autowired
    private DishMapper dishMapper;
    @Autowired
    private SetmealMapper setmealMapper;

    /**
     * 添加购物车
     */
    @Override
    public void addShoppingCart(ShoppingCartDTO shoppingCartDTO) {
        ShoppingCart shoppingCart = new ShoppingCart();
        BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);
        //获得当前用户id
        Long userId = BaseContext.getCurrentId();
        shoppingCart.setUserId(userId);
        //判断加入购物车的商品是否已存在
        List<ShoppingCart> shoppingCartList = shoppingCartMapper.list(shoppingCart);
        //如果已存在，更新，数量+1
        if (shoppingCartList.size() == 1) {
            shoppingCart = shoppingCartList.get(0);
            shoppingCart.setNumber(shoppingCart.getNumber() + 1);
            shoppingCartMapper.updateNumberById(shoppingCart);
        }
        //如果不存在，新增
        if (shoppingCartList.isEmpty()) {
            Long dishId = shoppingCart.getDishId();
            if (dishId != null) {
                Dish dish = dishMapper.getById(dishId);
                shoppingCart.setName(dish.getName());
                shoppingCart.setImage(dish.getImage());
                shoppingCart.setAmount(dish.getPrice());
            } else {
                Setmeal setmeal = setmealMapper.getById(shoppingCart.getSetmealId());
                shoppingCart.setName(setmeal.getName());
                shoppingCart.setImage(setmeal.getImage());
                shoppingCart.setAmount(setmeal.getPrice());
            }
            shoppingCart.setNumber(1);
            shoppingCart.setCreateTime(LocalDateTime.now());
            shoppingCartMapper.insert(shoppingCart);
        }
    }

    /**
     * 查看购物车
     * @return List<ShoppingCart>
     */
    @Override
    public List<ShoppingCart> showShoppingCart() {
        //得到用户id
        Long userId = BaseContext.getCurrentId();
        //根据用户id查询
        ShoppingCart shoppingCart = ShoppingCart.builder()
                .userId(userId)
                .build();
        return shoppingCartMapper.list(shoppingCart);
    }

    /**
     * 清空购物车
     */
    public void cleanShoppingCart() {
        //获取用户id
        Long userId = BaseContext.getCurrentId();
        //调用mapper层
        shoppingCartMapper.deleteByUserId(userId);
    }

    /**
     * 删除购物车中一个商品
     * @param shoppingCartDTO
     */
    public void subShoppingCart(ShoppingCartDTO shoppingCartDTO) {
        //复制数据到ShoppingCart类，加入用户id
        Long userId = BaseContext.getCurrentId();
        ShoppingCart shoppingCart = new ShoppingCart();
        BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);
        shoppingCart.setUserId(userId);
        //查询对应购物车信息
        List<ShoppingCart> shoppingCartList = shoppingCartMapper.list(shoppingCart);
        //如果number>1,进行-1,如果number=1，直接删除记录
        if (!shoppingCartList.isEmpty()) {
            shoppingCart = shoppingCartList.get(0);
            Integer number = shoppingCart.getNumber();
            if (number > 1){
                shoppingCart.setNumber(shoppingCart.getNumber() - 1);
                shoppingCartMapper.updateNumberById(shoppingCart);
            } else {
                shoppingCartMapper.deleteById(shoppingCart);
            }
        }
    }
}
